Formulation of Propolis Phenolic Acids Containing Microemulsions and Their Biopharmaceutical Characterization

Table 7

The fluxes of phenolic compounds from propolis microemulsions into skin layers after 24 hours.

Phenolic compounds	Flux ()
	PME (3 : 1) containing 7% IMP	PME (3 : 1) containing 6% IMP and 1% pine needle essential oil	PME (3 : 1) containing 6% IMP and 1% spruce needle essential oil
Epidermis
Vanillic acid	BLD	BLD	BLD
Caffeic acid	BLD	BLD	BLD
Vanillin	BLD	BLD	BLD
-Coumaric acid	BLD	ALD	ALD
Ferulic acid	BLD	BLD	BLD
Dermis
Vanillic acid	ALD	BLD	ALD
Caffeic acid	BLD	BLD	ALD
Vanillin	0.43 ± 0.10	0.49 ± 0.13	0.62 ± 0.14
-Coumaric acid	0.28 ± 0.10	0.34 ± 0.11	0.36 ± 0.10
Ferulic acid	ALD	ALD	0.35 ± 0.12

ALD: above limit of detection.
BLD: below limit of detection.